Two Easy Ways to Waterproof a Plywood Roof

If you need to waterproof a plywood roof, you’re in the right place here at PermaRoof UK. We’re happy to offer you all the support you need, from tips and expert advice to buying materials and installing them yourself or finding a reliable professional to do it for you.

Whether you’re waterproofing a plywood shed roof or preparing a garage deck for a green roof install, we’re here to help you get the job done right – first time.

Choosing the right materials

We believe in longevity at PermaRoof UK, providing materials designed for reliability over the long term, regardless of the size and scope of the project. There are two types of system we’d recommend for waterproofing over plywood – EPDM membrane and liquid PU coatings.

Depending on the project design, these two types of system are ideal for domestic waterproofing. Both suitable for installation over timber, and straightforward to apply for a competent DIYer.

Why choose EPDM membrane?

RubberCover EPDM membranes are perfect for most shed and flat roof waterproofing projects. Installed in a single sheet and with a service life expectancy of over 50 years, it offers a long term, easy to install solution for homeowners.

Ordering EPDM is fast and easy too, relying on accurate measurements, as we sell RubberCover by the metre or in a complete kit that includes everything you need in the right quantities. Kits are perfect for projects such as standard shed and garage roofing, and we provide an option to tailor a kit to your own specifications.

When to use liquid waterproofing

Liquid roofing is growing in popularity for domestic projects due to its flexibility over the widest range of surfaces. Over plywood, the system is straightforward to apply, requiring mixing and application with a series of rollers (like those you’d use for paint or roofing adhesive). A bandage is incorporated and the system cures quickly to form a membrane-like encapsulation of the surface.

A liquid PU waterproofing system is also the perfect approach in complex roofing designs where membrane installation is unsuitable or difficult. This might include designs with extrusions or complex angles or to provide a reliable base layer for green roofs or terraces.

We stock liquid roofing kits in two sizes – 5m2 and 10m2 – to suit most domestic plywood roof waterproofing projects.

How to prepare a plywood roof for waterproofing

Preparation is a key part of the project, especially if you’re replacing existing materials. First things first, though – prepare for the project by making sure you’ve accurately measured, calculated and gathered all the materials you need.

Waterproofing a new plywood roof will be straightforward, requiring minimal preparation of the timber surface, whether you’ve selected an EPDM membrane or a liquid approach. Make sure the entire surface is clean and dust-free.

Replacing existing waterproofing on a plywood roof will require more preparation time and some effort. First, strip back the old covering to ascertain the condition of the plywood deck, especially if there has been a leak or damage in the past. If you’re unsure, it may be better to call in a professional to take a look. This is well worth it in the longer term, as installing membrane or a liquid system over a damaged plywood roof deck may prove a costly mistake.

Feel free to browse our PDF guides containing all the basics to help you prepare for installing membrane. Visit the resource library here.

Further reading:

Can we help you to waterproof a plywood roof?

Regardless of whether you choose to waterproof a plywood roof with EPDM or a liquid solution, we are here to support you every step of the way. With a range of free, step-by-step guides and video tutorials and an award winning team of sales and customer support operatives, we’re here to guide you through. Call on 01773 608 839 or use the live chat for a quick query during working hours.

If you decide that DIY isn’t for you, we can also connect you with a reliable installer via our nationwide network. Trained, vetted and proven professionals, local to you. Find out more about the installer network here.

This is an updated version of a previously popular blog post. Read the original version here.

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